The present invention relates to a cleaning apparatus for a cooling water passage of an outboard motor having an improved structure.
In general, an engine of an outboard motor is cooled by taking a cooling water from an outside of the outboard motor, and accordingly, in a case where a sea water is used as such cooling water, a salt component contained in the sea water may stick to a cooling water passage of the outboard motor such as water jacket of the engine, which will result in corrosion to that portion. In order to eliminate such defect, it is necessary to periodically clean the cooling water passage with a pure water, and for this purpose, the outboard motor is provided with a cleaning apparatus for cleaning the cooling water passage, which is generally called as a flush system.
In such flush system, a cleaning water tube is connected at one end to the cooling water passage, another end of the cleaning water tube is connected to, for example, a connection portion formed to an engine cover, and a cooling water hose for supplying a cleaning water is connected to the connection portion from the outside thereof.
Such structure is, for example, disclosed in Japanese Patent Publication No. HEI 3-37322 (37322/1991), in which a connection portion is formed to an inner portion of an outside end of an inner passage of a conduit extending from an engine block, and the connection portion is formed with a screw thread to be coupled to a mail connector (standard size article) of a garden hose as a cleaning water hose.
Furthermore, Japanese Patent Laid-open (KOKAI) Publication No. HEI 7-269345 discloses a technology such that a hose is connected to the cooling water passage, a front end of the hose extends outside the outboard motor, and the front end thereof is formed with a connection portion to be coupled to a mail connector (standard size article) of a garden hose.
As mentioned above, in the described prior art, it is necessary to use the connector of the standard size article to be coupled to the connection portion.
Furthermore, in another prior art, there is also provided a structure in which an adapter is coupled to a cooling water passage and a general hose for city water is connected to the adapter or in which an ear-muffler-type adapter is applied to a cooling water intake port formed to a gear case and a general hose for city water is connected to the adapter.
However, with the structure using the connector of the standard article, it is necessary to use an adapter to be connected to a general hose for city water, thus being inconvenient.
Furthermore, the structure in which the front end of the connection hose is extended outside the outboard motor will not give a good outer appearance.
Still furthermore, when a cleaning water is supplied through the cooling water intake port, it is necessary to start the engine to drive a water pump, thus being inconvenient.